Apparatus and method for carrying out catalytic oxidation of ammonia with oxygen



" n'. 17 1923. T452 M5 p 4 l. W. CEDERBERG APPARATUS AND- METHOD FORCARRYING OUT CATALYTIC OXIDATION OF AMMONIA WITH OXYGEN Filed March 141922' would result a high increase of tempera-I- raramente. i?, icas.

nir ser insane arent ottica.

I'VAR WALFRID CEDEBIBERG,'OF BERLIN, GERMANY.

nrrnnnriis nien innrnon ron CARRYING cnr cnrninrric oxina'rion or WITHoxizemr.

Application tiled March 14, 1922. Serial Ho. 543,770.

To all whom may concern.' l

Be it known that I, IvAR WALFRID (JEDER- BERG, a subject of the King ofSweden, re-

siding at Berlin, Germany, have invented a new and useful Im rovement inApparatus and Method for` arrying Out Catalytic Oxidation of Ammoniawith Gxygen, of which the following is aspeciication.

In certain cases great technical diiiculties are `met with in carryingout such catalytic reactionsa between gases which. involve thegeneration of very high heat. This is the case for instance in thecatalytic oxidation of ammonia by the use'of pure oxygen instead of airor other mixtures containing oxygen. The Eeaction of ammonia by means ofoxygen would in volve considerable practical advantages, it

has been a desideratum to be able to carry out the said reactionon atechnical scale.

Now, the present invention refers ,to an apparatus and method by meansof which catalytic oxidation of ammonia by means of oxygen may becarried out without the risk of too highan increase of temperature andwithout danger of explosion. The invention is based on the discoverythat a catalytic combustion of ammonia-oxygen mixtures containing up to35 to 40 per centV ammonia may be carried out without danger ofexplosion, by the catalyst, 'for instance nely divided platinum, beingprecipitated' oncontact carriers in such manner that the concentrationof the catalyst in the zone of combustion is gradually'increased,'for'instance in a geometrical or arithmetical progress1on,so

that the concentration is least in the portion of the catalyst where thegas mixture enters', and ishighest where the gases of reaction aredischarged. In this manner it is attained f that the principalcombustion is not locaiized to the front portions of the catalyst, whichture and danger of explosion, but is distributed within theentire zoneof combustion.

The apparatus according to the present invention consists 'in well knownmanner of a low vessel in which there is a catalyst zone, and is thusthat within said zone the concentration of the catalyst is increasedfrom the inlet end ltowards the outlet end of the vessel.

In the accompanying drawing an embodi ment of an apparatus according tothe invention is illustrated diagrammatically, F ig.

l showing a longitudinal section and F ig. 2

.annoiare principally characterized by this' In the spacesformed-between the diderent nettings 3 contact carriers, for instance inthe shape of porous plates tot pumioe-stone,

Iare placed on which plates the catalyst has been precipitated with avarying concentration, so that the concentration of the catalyst isincreased from the inlet end5 towards the outlet end 6. The metalnettings 3` and the rings 2 serve to conduct heat from the combustionzone and to increase the radiation of heat from the same sothat too highan increase of the temperature is avoided.

I claim: v

l. An apparatus for carrying out catalytic oxidation of ammonia withoxygen, comprising a Ho veel in which there isa catalyst zone, an acatalyst i said zone the concentration of which cata yst increases fromthe inlet end towards the outlet end of thev vessel.

- 2. An apparatus for carrying out catalytic oxidation of ammonia withoxygen, comprising a flow vessel in which there is a-catalyst zone,catalyst units in said zone said' units having different concentrationincreasin from the inlet end towards the outlet end o said vessel, andheat .conductors of catalytically inactive material placed between" saidunits.

3. An apparatiis *for carrying out catalytic oxidation of amnra'nia withoxygen, comprising a flow vesselii which there is a catalyst zone,catalyst units: in said zone said units ioe ict

" hving dierent concentration increasinv from theinlet end towards theoutlet en of said vessel, and heat conductors of catalyt- Jlt saidunits.

4., A method for the catalytic oxidation of vainnmoniaii with oxyn,which consists in ically inactive metal netting placed. between,

Mam@

passing a mixture of ammonia and oxygen through a. catalyst zone, theconcentration of said catalyst in the zone of combustion being '10increased in the direction in which the gases flow.` -4

" WAR WALERID CEDERBERG;

